Move the new WebUI's code to read the data off the IO thread as it's generally from the memory-mapp…

content/browser/webui/url_data_manager_backend.cc

Index: content/browser/webui/url_data_manager_backend.cc
diff --git a/content/browser/webui/url_data_manager_backend.cc b/content/browser/webui/url_data_manager_backend.cc
index 861261846dd40bea82ad27dd6746a429dbb738f8..fa7c08d9023bfbea0f172c4dc9fd4b058e6f1f01 100644
--- a/content/browser/webui/url_data_manager_backend.cc
+++ b/content/browser/webui/url_data_manager_backend.cc
@@ -510,7 +510,8 @@ bool URLDataManagerBackend::HasPendingJob(
 
 bool URLDataManagerBackend::StartRequest(const net::URLRequest* request,
                                          URLRequestChromeJob* job) {
-  // NOTE: this duplicates code in web_ui_url_loader_factory.cc's URLLoaderImpl.
+  // NOTE: this duplicates code in web_ui_url_loader_factory.cc's
+  // StartURLLoader.
   if (!CheckURLIsValid(request->url()))
     return false;